This invention relates to the analysis of vibrating panels, and more particularly to apparatus for detecting the amplitude, frequency or modes of vibration of a panel which is vibrating.
One conventional way of analysing vibrating panels, for example to test their ability to withstand certain types of treatment, consists of attaching accelerometers to the specimen panel in various places. The electrical signals produced by the accelerometers are recorded and analysed in a way known to those skilled in the art to produce the information required about the panel in question.
The accelerometers used in this type of testing are expensive, and many of them are required for a single testing operation. Thus, the testing is expensive and time consuming. Furthermore, in some cases such as the acoustic fatigue testing of vibrating panels in hot environments, it is not possible to use such techniques and a contactless system is required.